The incident occurred less than a month after Seoul vowed to use force to keep Chinese fishing trawlers from continuing to invade Korean waters.

The South China Morning Post reports that the South Korean government seized two Chinese trawlers of “some 30 Chinese fishing boats” illegally present in Korea on Tuesday after opening fire with machine guns. “They tried to ram our ships although we repeatedly warned them,” Senior coastguard official Kim Jung-shik explained. “I thought our officers would be in danger if I allowed any more resistance so we ended up using the crew service weapon.” Neither side reported injuries following the incident.

Chinese Foreign Ministry spokeswoman Hua Chunying issued a statement on Wednesday condemning the government of President Park Geun-hye. “Using destructive weapons can easily injure fishermen and we urge the ROK [South Korea] side to… avoid using any excessive or extreme tools in their law enforcement activities,” she protested. “The Chinese side has said many times that responsible government agencies attach great importance to and vigorously strengthening the management and control of Chinese fishermen’s activities.”

China has repeatedly used force against foreign fishing boats they claim to be trespassing in Chinese waters. In the South China Sea, Chinese coast guard officials have on multiple occasions attacked Philippine and Vietnamese fishermen near the Spratly and Paracel Islands, sinking some ships and injuring their crew.

On Thursday, Korean officials openly rejected Hua’s statement.

“We cannot accept China taking issue with our Coast Guard’s law enforcement methods including the use of such crew-served weapons,” South Korean Foreign Ministry spokesman Cho June-hyuck told reporters. “The main reason for the use of the weapon is illegal fishing conducted by Chinese vessels and their organized and violent resisting of arrest. China should take effective measures aimed at stamping out illegal fishing by its boats and the violent behavior of the crew.”

While embattled president Park has worked to thaw relations between South Korea and China significantly during her tenure, tipping the balance of powers in Beijing closer to Seoul than Pyongyang, South Korea warned in October that it would change its policy towards China’s intrusions, employing the use of force to keep Chinese fishermen out of Korean waters.

While China maintains territorial disputes with Malaysia, Brunei, Vietnam, Taiwan, the Philippines, Indonesia, and Japan, the incursion of Chinese vessels into Korean waters is especially egregious because China does not claim this as its exclusive economic zone (EEZ). The only existing territorial dispute between Seoul and Beijing is the Ieodo or Suyan rock in the East China Sea, which both claim but, as maritime law does not designate rocks as “territory,” these claims do not confer rights upon the owner.

Chinese ships have regularly violated the sovereignty of foreign nations for years, both near and far. Japan has repeatedly demanded Chinese ships stay far from its Senkaku Islands, which China claims; Indonesia has used force to remove Chinese ships from its waters on multiple occasions this year; and, in March, Argentina sunk an interloping Chinese ship off its waters.